Single stage bi-directional pump

ABSTRACT

This invention discloses a bi-directional turbine pump where rotation of a pump impeller in one direction provides a discharge to one discharge line and rotation of the pump impeller in the other direction provides a discharge to another discharge line. The pump is specifically designed to provide a lower quantity of delivered fluid when rotating in one direction, and is optimized for a given impeller to provide the highest quantity of delivered fluid possible for a given speed of rotation for the opposite discharge. The maximized fluid delivery is obtained by placing both discharges tangential to the pump chamber and situating the pump inlet on the same side, with this inlet supplying fluid to the pump mediately between the two discharges. With such a configuration, not only is discharge maximized for one direction of impeller rotation, but also no fluid is delivered through that discharge line which should be in an inactive condition based on impeller direction.

United States Patent [1 1 Chow et al.

{ 1 SINGLE STAGE BI-DIRECTIONAL PUMP [75] Inventors: Shin-Kien Chow; Kent T. S. Tzou,

21 Appl. No.: 162,044

[52] US. Cl. 415/152 A, 415/219 C, 415/206 [51] Int. Cl. F04d 17/08, F01d 1/30 [58] Field of Search 415/129, 204, 206, 415/213 T, 53 T, 152 A, 219 C [56] References Cited UNITED STATES PATENTS 2,916,997 12/1959 Terrie 415/206 3,040,663 6/1962 Cushing..... 415/213 T 3,136,254 6/1964 Douglas 415/206 2,258,284 10/1941 Findley 415/204 l,883,634 10/1932 Easton 415/213 T 772,989 10/1904 Williams 415/152 A FOREIGN PATENTS OR APPLICATlONS 902,298 l/1954 Germany 415/206 931,390 8/1955 Germany 11 a y h- 2 Nov. 20, 1973 Primary Examiner-l-lenry F. Raduazo Att0rneyF. H. Henson et al.

[57] ABSTRACT This invention discloses a bi-directional turbine pump where rotation of a pump impeller in one direction 1 provides a discharge to one discharge line and rotation of the pump impeller in the other direction provides a discharge to another discharge line. The pump is specifically designed to provide a lower quantity of delivered fluid when rotating in one direction, and is optimized for a given impeller to provide the highest quantity of delivered fluid possible for a given speed of rotation for the opposite discharge. The maximized fluid delivery is obtained by placing both discharges tangential to the pump chamber and situating the pump inlet on the same side, with this inlet supplying fluid to the pump mediately between the two discharges. With such a configuration, not only is discharge maximized for one direction of impeller rotation, but also no fluid is delivered through that discharge line which should be in an inactive condition based on impeller direction.

5 Claims, 3 Drawing Figures SINGLE STAGEEBI-DIRECTIONAL PUMP BACKGROUND OF THE INVENTION 1. Field of the Invention:

The invention relates to a bi-directional turbine pump, and more specifically, relates to a bi-directional turbine pump with fluid delivery selectively through two different discharges, dependent on impeller rotation,and readily adaptable for use in a modern clothes washing applicance or the like.

2. Description of the Prior Art 1'! he use of bi-directional' pumps in washing machines, for example, is-well known, the same being provided so that a convenient and=.easy discharge may be had for the wash water from -the wash tub to a convenient drain, and alternately,for the wash water to be recirculated within the washing machine. Water recirculation requirements, however, are usually somewhat less than the pumping requirements for washing machine drainage since only a short time is desired for the washing machine to be drained, while recirculation of wash or rinse water within the washing machine must be limited to a lower flow rate sothat water is properly filtered as it passes ba c k into and drains downwardly within the washing. machine. Standard configuration impellers such as illustrated and described in U. S. Pat. Nos. 3,136,254and 3,359,908'issued, respectively, on June 9, 1964 and Dec. 26, 1967, have been designed specifically to provide a lesser flow rate for one direction of their-rotation; but these-pumps, because of the shaping of their impeller blades-and the location of their inlets and outlets, .are subject-to a great deal of turbulence within the pump housing so that an aeration condition may occur. This results-in a sudsing of the wash or rinse water being pumped. Since a high suds level is undesirable in the washing or rinsing of clothes, the use of a standard impeller configuration with modified inlets and outletswhich provided for rapid discharge and did not cause aeration problems would be advantageous for the pumping of the water in a clothes washing machine.

Accordingly, in order to obtain a maximum flow rate 'TfOl' drainage purposes for such a machine, with a given revolution speed of the impeller and standard impeller configuration, and yet one that did not create aeration problems in either direction of its pumping, it would be advantageousto arrange the discharge and inlet means for a-pump so that the pump provided a maximum discharge drainage flow, limited aeration and no tendency to pump fluid through-the unwanted discharge.

SUMMARY OF THE INVENTION The invention provides a bi-directional turbine pump in which an impeller is rotated to pump water, selectively, depending on its direction of rotation. In one direction of impeller rotation, the pump discharges to a discharge line in the pump housing that leads to a drain fora washing machine or the like with which the pump is disposed. In the other direction of impeller rotation, discharge'is to a line that leads to a recirculating system for the washing machine or the like so that water may be continuously circulated and filtered during the clothes washing cycle. A fluid inlet to the pump is provided on the upper side of the housing for the same with its supply to the pump being at the periphery of the pumping chamber downwardly mediately between the discharge lines. Each of the discharge lines is situated so that the flow outwardly therefrom is tangential to the pumping chamber, with these outlets being disposed at substantially relative to each other in the embodiment illustrated.

The impeller utilized in the invention is a conventional one, comprising four curved blades equally spaced around a central mounting pivot for the impeller. The impeller is situated within the pump chamber so that the highest efficiency side of the blades is active for pumping water to the discharge line which would normally be connected to the drain of the washing machine. Because of the tangential arrangement of the discharge lines and the mediate disposition of the inlet between these two drain lines, discharge flow is maximized for the particular impeller involved. At the same time, pumping out of the undesired discharge line does not occur, partially due to the positioning of the inlet, giving the pumped water the longest available run as it is pumped around the chamber periphery. The instant turbine pump also has no undesired aeration characteristics in either direction of pump rotation.

DRAWING DESCRIPTION For a better understanding of the invention, reference maybe had to the preferred embodiment, exemplary of the invention, shown in the accompanying drawings in which:

FIG. 1 is a cross sectional view of the lower pump housing and included impeller;

FIG. 2 is a cross sectional view taken generally on line II-II of FIG. 1 and also showing the upper housing portion and water inlet; and

FIG. 3 is a perspective view of the assembled pump.

DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to FIGS. 1 to 3, it can be seen that a bi-directional turbine pump 10 includes an upper housing portion 12 and a lower housing portion 14. A series of bolts 16 extend through bolt holes 18 and 20 formed in the upper and lower housing portions, respectively, to maintain the upper and lower housing portions of the turbine pump 10 in assembled relationship. An 0 ring 22 extends within an annular groove 24 formed in upper pump housing portion 12, with the O ring 22 being compressed by an axially extending, annular projection 26 on the lower pump housing 14. The annular projection 26 is, of course, insertingly held in the annular groove 24 by means of the threaded insertion of bolts 16 in lower housing portion 14. Thus, the upper and lower pump housing portions 12 and 14 are assembled in a liquid tight relationship.

The lower housing portion 14 has a pump chamber 28 formed therein having a generally circular periphery. Received within pump chamber 28 is an impeller 30 having a series of four equally spaced, curvic blades 32, with the curvic blades 32 providing for pumping action of water within turbine pump 10 as the impeller 30 rotates. The impeller 30 has centrally located therein a bore 34 having one flat face 36. The bore 34 receives a driven shaft 38 therein having a corresponding flat face on its upper end that insures that there is no relative rotation between the impeller 30 and shaft 38. As is seen most clearly in FIG. 2, shaft 38 extends up wardly into lower pump housing portion 14 centrally thereof so as to receive on its upper end the impeller An ring 40 seals the bottom portion of lower housing portion 14 so that there is no leakage through a bore 42, provided for the insertion of shaft 38 into housing portion 14. The shaft 38 is driven by any conventional motor drive arrangement (not shown), it being sufficient to note that the motor must be capable of rotation in both directions so that impeller 30 is also capable of being rotated in both directions.

A pair of discharge outlets 44 and 46 are provided for turbine pump 10, with these outlets being circular in cross sectional shape and formed in lower housing portion 14. Outlet 44 is provided for connection to a drain (not shown) for a washing machine (not shown), while outlet 46 is provided for connection to a recirculating line (not shown) for the washing machine with which turbine pump is to be utilized. Each of these outlets is identical in size, both having the same diameter, and each is tangentially arranged relative to the general periphery of pump chamber 28. The outlets 44 and 46 are also shown substantially disposed at a right angle relative to each other, the purpose of which will soon be described. The impeller 30, as is conventional, rotates in a counterclockwise direction for pump drainage through outlet 44 and rotates clockwise for pump drainage through outlet 46.

An inlet 48 is formed in the top housing portion 12 so that inlet water is discharged to pump chamber 28 mediately between the outlets 44 and 46 and generally at the periphery of pump chamber 28. As can be most clearly seen in FIGS. 1 and 3, the inlet 48 supplies the discharge water in that area 29 of pump chamber 28 having the largest peripheral extent between the outlets 44 and 46. More specifically, inlet 48 supplies water to the pump 10 on that portion of the periphery of pump chamber 28 which provides a substantial annular extent for setting up driving rotation of the water by impeller 30 in the pump chamber 28. Thus, the previously described location of outlets 44 and 46 at substantially 90 angle relative to one another provides the area 29 that is situated on the portion of the periphery of pump chamber 28 opposite to the apex forming the 90 angle and between the outlets 44, 46. With the inlet 48 so situated and the drain outlet 44 disposed at a tangential relationship to the periphery of pump chamber 28, flow is maximized for drainage purposes through outlet 44. Further, because of the annular extent of area 29, no back pumping through the undesired outlet 46 occurs and no problems are encountered with aeration. Since the outlet 46 is also tangential to pump 28, its discharge is also maximized relative to the speed and shaping of impeller 30, and turbulence is thereby reduced. Again, it should be noted, with impeller 30 rotating to provide a flow through outlet 46, that no pumpback through outlet 44 is occasioned.

It should also be noted that the angle between the outlets 44 and 46 can be increased to substantially 135, with the inlet 48 still disposed mediate relative to this angle, and flow will still be optimized for the outlet 44, but that an increase of the angle above 135 will cause air locking problems to turbine pump 10 so that such an angular relationship is not desired. Of course, below an angle of insufficient annular area is provided between the two outlets so that the flow is not maximized, and back pumping may occur.

It should be clear to one skilled in the art that a bidirectional turbine pump has been described that fulfills the advantages set out in the beginning portion of the description, and it should also be clear to one skilled in the art that many modifications can be made therein which would still fall within the spirit and purview of the description offered.

We claim as our invention:

1. A bi-direction pump including;

a pump housing defining an annular pumping chamber having a substantially smooth outer peripheral wall;

a reversibly rotatable impeller disposed within said chamber, said impeller defining blade structure for pumping fluid in either direction of rotation;

said outer peripheral wall defining a pair of outlets communicating with said annular chamber, one of said outlets directed so as to primarily discharge fluid when said impeller is rotated in one direction and the other of said outlets directed so as to primarily discharge fluid when said impeller is rotated in the opposite direction;

said housing further defining an inlet communicating with said pumping chamber generally adjacent said outer peripheral wall and disposed between said outlets such that when said impeller is rotated in said one direction said blade structure, in moving from across said inlet to across said one of said outlets, must pass across said other of said outlets, and when said impeller is rotated in said opposite direction said blade structure, in moving from across said inlet to across said other of said outlets, must pass across said one of said outlets;

whereby, during a pumping operation at least a limited amount of fluid pressure is maintained at the outlet not receiving the fluid for discharge.

2. Structure according to claim 1 wherein both said one and said other of said outlets are disposed generally tangentially to said outer peripheral wall.

3. Structure according to claim 2 wherein both of said outlets are of substantially the same size.

4. Structure according to claim 3 wherein said blade structure provides distinct pumping capacities in each direction of rotation whereby said pump discharges a greater volume when said impeller is rotated in said one direction than when said impeller is rotated in said opposite direction at the same angular speed.

5. Structure according to claim 2 wherein said outlets are disposed at generally right angles to each other and said inlet is disposed generally diametrically opposed to the right angle apex. 

1. A bi-direction pump including; a pump housing defining an annular pumping chamber having a substantially smooth outer peripheral wall; a reversibly rotatable impeller disposed within said chamber, said impeller defining blade structure for pumping fluid in either direction of rotation; said outer peripheral wall defining a pair of outlets communicating with said annular chamber, one of said outlets directed so as to primarily discharge fluid when said impeller is rotated in one direction and the other of said outlets directed so as to primarily discharge fluid when said impeller is rotated in the opposite direction; said housing further defining an inlet communicating with said pumping chamber generally adjacent said outer peripheral wall and disposed between said outlets such that when said impeller is rotated in said one direction said blade structure, in moving from across said inlet to across said one of said outlets, must pass across said other of said outlets, and when said impeller is rotated in said opposite direction said blade structure, in moving from across said inlet to across said other of said outlets, must pass across said one of said outlets; whereby, during a pumping operation at least a limited amount of fluid pressure is maintained at the outlet not receiving the fluid for discharge.
 2. Structure according to claim 1 wherein both said one and said other of said outlets are disposed generally tangentially to said outer peripheral wall.
 3. Structure according to claim 2 wherein both of said outlets are of substantially the same size.
 4. Structure according to claim 3 wherein said blade structure provides distinct pumping capacities in each direction of rotation whereby said pump discharges a greater volume when said impeller is rotated in said one direction than when said impeller is rotated in said opposite direction at the same angular speed.
 5. Structure according to claim 2 wherein said outlets are disposed at generally right angles to each other and said inlet is disposed generally diametrically opposed to the right angle apex. 